Research summary
What Qualifies as a Probiotic, and Why Strain Matters
Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Their effects are strain-specific: evidence for one strain or product does not necessarily apply to others.[1]
The consensus definition
Under the expert consensus on the scope and use of the term, probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.[1]
Why effects are strain-specific
The effects of probiotics are strain-specific. A benefit demonstrated for one specific strain or product does not necessarily apply to others, so evidence for a specific strain should not be generalized to all probiotics.[1]
What this does and does not tell you
This page describes the consensus definition and the principle of strain specificity. It does not establish any specific health benefit for any particular product, and a benefit shown for one strain should not be assumed to apply to probiotics in general.[1]
References
- Expert consensus document. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature Reviews Gastroenterology & Hepatology. 2014. Expert consensus statement View source →